Pipe guide



Jan. 12, 1932. J. G. SNIFFIN ET AL PIPE GUIDE Filed Jan. 16, 1930Patented 1dan. 12, 1932 i UNITED STATES PATENT oEFIcE JOHN G. SNIFFIN, FMAYWOOD, AND PETER HAMMER, OF BREA, CALIFORNIA PIPE GUIDE Applicationled January 16, 1930. Serial No. 421,122.

This invention is a guide for centering` pipe, and is particularlyapplicable to oil field practice for centering casing and perforatedpipe so that cement may-be uniformly distributed and perforated pipe maybe unilformly spaced from the surrounding well iore.

It is an object of the invention to mount a normally contracted guide ona string of casing so that i-t may be positively expanded to operativeposition engaging the wall of the bore when the casing has been loweredinto the well, thereby centering the casing in the bore and providing auniform surrounding l5 space for discharge of cement or flow of oil intothe casing through usual perforated pipe.

It is a further object of the invention to provide a guide whichpreferably operative- '0 ly engages the wall of the bore at axiallyspaced points so as to insure centering of the casing throughout anydesired length.

It is a still further object of the invention to adapt the guide forpositively limiting 2 lowering of a string of casing into a well so asto position a cementing shoe or the like at any desired level.

It is a still further objectl of the invention to expand the guide bymeans of a telescopic engagement which is operated by continued loweringof the upper portion of the string of casing after its lower portion hasanchored on the bottom of the wellbore, the arrange ment of parts beingsuch as to positively support the string of casing after it has beentelescoped for expanding the guide, and the expanded guide preferablyhaving vmeans for locking it against accidental contraction as 'a resultof movement of the casing when being stretched, etc.

Further objects of the invention will be readily understood from thefollowing description of the accompanying drawings, in which:

Fig. l'is a side elevation, partly in axial section, showi-ng the guidecontracted and adapted forfuse in connection with a cementing shoe.

Fig. 2 is a similar view with the guide expanded to operative position.

Figs. 3 and 4 are transverse sections on the lines 3 3 and 4 4respectively of Fig. 1.

Fig. 5 is a view similar to Fig. l but showing the guide employed inconnection with usual perforated pipe.

The guide may be employed in connection With a string of well casingwhich is adapted for usual suspension from a draw works (not shown) forlowering the casing string 1into a Well bore, with the casing stringcomprising usual casing lengths l connected by coupling collars 2, andas illustrated at Fig. 1 preferably having a depending cementing shoe 3;and the guide comprises axially extending arms overlying the casing andadapted for radial expansion so as to engage the Well bore and centerthe cementing shoe for uniform distribution of cement.

The arms are preferably expanded by movement of the string of casingrelative thereto, and for this purpose are mounted on an anchoring meanswhich is adapted to rest on the bottom of the well bore so as to permitlowering of the casing relative to the anchored arms, with the string ofcasing having means for engaging the arms so as to expand the same. Theanchoring means is preferably a length of casing 4 which may have aguide shoe 5 at its lower end, and circumferentially spaced arms 6project upwardly from casing 4 for free sliding fit in longitudinalgrooves 7 of cementing shoe 3, and are connected at their upper ends bya collar 8 which is adapted to rest on an exterior shoulder 9 at theupper end of the cementing shoe. A second set of circumferentiallyspaced arms 10 are preferably adapted for sliding fit in longitudinalgrooves 11 of couling 2, and are connected at their lower 'end y acollar' 12 which is adapted to rest on collar 8, with annular bands 13preferably connecting the arms 10 at suitable longitudinally spacedpoints. l The anchor 4 together with arms 6 and collar 8 are preferablyformed from an integral length of casing which is suitably cut-out toform the circumferentially spaced arms, and the collar 8 which is a partof this length of casing is split as shown at 14 so that arms 6 may beseated in grooves 7 with the collar seating on shoulder 9, and thecollar then welded at its split as shown in Fig. 1. In similar manner asuitable integral length of casing is preferably cut-out to form thecircumferentially spaced arms 10 together with their collar 12 and bands13, and this unitary structure may be operatively mounted on casing 1wit-h arms 10 projecting upwardly for reception in the cooperatinggrooves l1 which may be formed in one 0r more of the coupling collars 2,and the casing 1 is then threaded into cementing shoe 3 for assemblingthe parts.

When lowering the assembled structure into a well the collar 8 restsupon shoulder 9 with the upper end of anchor 4 appreciably spaced belowcementing shoe 3 as shown in Fig. l, so that when the anchor strikes thebottom of the well bore continued lowering of the string of casing willtelescope shoe 3 relative to arms 6 until the cementing shoe rests uponthe open upper end of the anchor as shown in F ig. 2; and by thustelescoping shoe 3 relative to anchored arms 6, the one or morecouplings 2 which arms 1 0 overlie, are similarly longitudinally shiftedrelative to said overlying arms which are supported by their collar 12resting upon collar 3.

This longitudinal movement of shoe 3 and coupling 2 relative to arms6-10 is adapted to radially expand the arms so as to engage thesurrounding well bore and thereby center the string and thus provide auniform surrounding space; and for this purpose a longitudinal wedgingengagement is provided between grooves 7-11 and the coop- @rating arms6-10. As an instance of this arrangement the grooves 7-11 may taper to agradually increasing diameter toward their upper ends, with cooperatingwedges 15-16 on arms 6 1() engaging the tapering grooves when the stringof casing is lowered relative to the anchored arms.

Vhen the arms have been expanded so as to center the telescoped stringof casing which is supported on anchor 4, the parts are preferablylocked against accidental release, as for example by providing fingers17 at the lower ends of wedges 15--16 adapted for automatic engagementin cooperating slots 18 which are formed in the grooves 7-11.

With the string of casing thus centered and anchored in the well bore,it may be cemented in usual manner, the cementing shoe 3 being shown asadapted for axial discharge of cement into anchor 4, from which thecement may discharge through suitable perforations 19, and from whichthe cement will also discharge through the upwardly cxtending grooves 7when the cement overflows the anchor. In order to positively directcement upwardly for discharge from anchor 4 through grooves 7, aperforated baflie 20 may extend across anchor 4 immediately be- 10W thetelescoped cementing shoe, so that while a part of the cement will flowthrough the perforations of the baffle for discharge through openings19, the major portion of the cement will be directed upwardly bystriking the baffle and will thus discharge through grooves 7. Thecement is thus uniformly distributed, due to the centering of shoe 3 inthe well bore, and the anchor 4 forms a reinforcement in the body ofcement which is discharged into the well.

In practice the anchor 4 may be of any predetermined length adapted toposition the cementng shoe 3 at any desired level, and depending uponthe formation encountered, the arms 6-10 define circumferences of suchdiameter and bearing such relation to the expanding action of wedges'15-16 as to expand the arms for predetermined penetration of thesurrounding well bore when shoe 3 seats on anchor 4.

The guide may be employed for centering pipe other than merely acemented string of well casing. Thus for example, and as shown at Fig.5, the guide may be employed to center a usual string of perforated pipeso as to insure uniform flow of oil through the perforations. For thispurpose the anchor 4 is replaced by a usual string of perforated pipe 4awhich may be of any desired length and which is adapted to seat on thebottom of the well bore as previously described, with arms 6 projectingupwardly from the perforated pipe and cooperating with a shoe 3suspended from a string of casing 1, so that when the string of casingis lowered relative to the anchored arms the shoe 3n will expand thearms for centering the perforated pipe as previously described, and willseat in the open upper end of the perforated pipe and thus form a usualcasing string having a perforated lower end.

fe have thus provided an extremely practical guide for pipe such as wellcasing which is adapted to be lowered into a well bore, the guide beingnormally contracted for unobstructed lowering of the casing but adaptedfor positive expansion so as to center the casing in the bore, and theinvention also providing for locking the guide in operative position andaxially supporting the string of casing when it has been lowered to thedesired level.

We claim:

1. In combination, a suspended string of Well casing adapted to belowered in a well bore, a shoe at the lower end of the casing havinglongitudinal exterior grooves, a supporting shoulder at the upper end ofthe shoe, an annulus having upstanding spring arms slidably received inthe grooves, a collar connecting the upper ends of the spring arms andadapted to rest upon the supporting shoulder for normally suspending theannulus in longitudinally spaced relation below the shoe so that theannulus is adapted to anchor upon the bottom of the well bore when thecasing string is lowered in the well, the suspension of the casingstring adapting it for lowering relative to the anchored annulus andthereby telescoping4 the shoe relative to the anchored annulus, the shoehaving a bore opening through its lower end, the grooves in the shoeconvergently tapering toward their lower ends for communication with thebore of the annulus when the shoe is telescoped relative thereto,wedging elements medially of the spring arms cooperating with thetapering grooves for radially bowing the spring arms medially of theirlength when the shoe is telescoped relative to the anchored annulus, thebowed spring arms being adapted to engage the wall of the well bore forcentering the telescoped shoe, and means for locking the shoe in itstelescoped position. e

2. In combination, a suspended string of well casing adapted to belowered in a well bore, a shoe at the lower end of the casing havinglongitudinal exterior groovesg a supporting shoulder at the upper end ofthe shoe, an annulus having upstanding spring arms slidably received inthe grooves, a collar connecting the upper ends of the spring arms andadapted to rest upon the supporting shoulder for normally suspending theannulus'in longitudinally spaced relation below the shoe so that theannulus is adapted to anchor upon the bottom of the well bore when thecasing string is lowered in the well,

the suspension of the casing string adaptingv it for lowering relativeto the anchored annulus, the grooves in the shoe convergent-ly taperingtoward their lower ends, and wedg-A ing elements medially of the springarms cooperating with the tapering grooves for radially bowing thespring arms medially of their length when the shoe is lowered relativeto the anchored annulus, the bowed spring arms beine' adapted to engagethe wall of the well bore igor centering the shoe.

3. In combination, a suspended string of well casing adapted to belowered in a well bore, a shoe at the lower end of the casing havinglongitudinal exterior grooves, an annulus having upstanding spring armsslidably received in the grooves and normally suspending the annulus inlongitudinally spaced relation below the shoe so that the annulus isadapted to` anchor upon the bottom of the well` bore .when the casingstring is lowered in the well, the suspension of the casing stringadapting it for lowering relative to the anchored annulus and therebytelescoping the shoe relative to the anchored annulus, the shoe having abore opening through its lower end, the grooves in the shoe convergentlytapering toward their lower ends `for communication with the bore of theannulus when the shoe is telescoped relatlvefor radially expanding thespring arms when 1 the shoe is telescoped relative to the .anchoredannulus, the expanded arms being adapted to engage the wall of the wellbore for centering thetelescoped shoe.

4. In combination, a suspended string of well casing adapted to belowered in a well bore, a shoe at the lower end of the casing havinglongitudinal exterior grooves, an annulus having upstanding spring armsslidably received in the grooves and normally suspending the annulus inlongitudinally spaced relation below the shoe so that the annulus isadapted to anchor upon the bottom of the well bore when the casingstring is lowered in the well, the suspension o'f the cas- -ing stringadapting it for lowering relative to the anchored annulus, the groovesin the shoe convergently tapering toward their lowler ends, and wedgingelements on the spring arms cooperating with the tapering grooves forradially expanding the spring arms when the shoe is lowered relative tothe anchored annulus, the expanded arms being adapted to engage the Wallof the well bore for centering the shoe.

5. In combination, a suspended string of well casing adapted to belowered in a well bore, a shoe at the lower end of the casing havinglongitudinal exterior grooves, an annulus having upstanding spring armsslidably received in the grooves and normally suspending the annulus inlongitudinally spaced relation below the shoe so that the annulus isadapted to anchor upon the bottom of the well bore when the casingstring is lowered in the well, the suspension of the casshoeconvergently tapering toward their lower ends, wedging elements on thespring arms cooperating with the tapering grooves for radially expandingthe spring arms when the shoe is lowered relative to the anchoredannulus, the expanded arms being adapted to engage the wall of the wellbore for centering the shoe, and means for locking the shoe in loweredposition with relation to the anchored annulus.

6. In combination, a suspended string of well casing adapted to belowered in a well bore, the casing string having exterior longitudinalgrooves, longitudinal spring arms slidable in the grooves relative tothe casing and normally lying iat in the grooves, means for anchoringthe spring arms in the well fbore, the 'suspension of the casing stringCil wall of the well bore for centering the casing string.

7. In combination, a suspended string ot well easing adapted to belowered in a well bore, normally radially retracted guide elementsslidably mounted on the casing` and having` an abutment elementsuspended therefrom so that the abutment element is adapted to anchorupon the bottom of the well bore when the casing string is lowered inthe well, the suspension of the casing string adapting it for loweringrelative to the anchored abutment elen'ient, and means for radiallyyexpanding the guide elements by lowering the casing string relative tothe anchored abutment element, the radially expamiled guide elementsbeing adapted to engage the wall ot the well bore for centering thecasing string.

8. In combination, a suspended string ot well casing adapted to belowered in a wel! bore, normally radially retracted guide elementsslidably mounted on the casing and having an abutment elei'nentsuspended therefrom so that the abutn'ient element is adapted to anchorupon the bottom oi" the well bore when the casing string is lowered inthe well, the suspension ot the casingr string adapting it for loweringrelative to the anchored abutment element, meansfor radially exprridingthe guide elements by lowering the easing string relative to theanchored abutment element, the radially expanded guide elementsbeingadapted to engage the wall ot the well bore for centering` theeasing string, and means for locking the casingl string in loweredposition with relation to the anchored abutment.

9. In combination, a suspended string ot" for anchoring the guideelements in the well bore, the suspension of the casing adapting it forlowering relative to the anchored guide elements, means for radiallyexpanding the guide elements by lowering the casing string relative tothe anchored gude elements, the radially expanded guide elements beingadapted to engage the wall ot' the well bore for centering` the casingstring, and means tor locking the casing in lowered position withrelation to the anchored guide elements.

l0. In combination, a suspended string of well casing adapted to belowered in a well bore, normally radially retracted guide elementsslidably mounted on the casing, a supporting shoulder on the casing, acollar connecting` the upper ends of the guide eleu'ients and adapted torest upon the supporting` shoulder, means for anchoring the guideelements in the well bore,4 the lsuspension of the casing adapting itfor lowering relative to the anchored guide elements, and means forradially expanding the guide elements by lowering the casing stringrelative to the an- -the anchored annulus and thereby telescoping thecasingv relative to the anchored annulus, the grooves in the casingcommunicating with the bore of the annulus when the casing is telescopedrelative thereto, thereby providing tor discharge from the casing intothe annulus and thence through the grooves into the surrounding wellbore, and means for radially expanding the guide elements by saidlowering ot' the casing relative to the anchored annulus.y the radiallyexpanded guide elements bein;r adapted to engage the wall of the wellbore tor centering the casing string.

In testimony Whereotl we have alixed our signatures.

.IUI-IN G. SNIFFIN. PETER HAMMER.

